Professional service assurance for IPTV
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By Zhang Wei, Wang Yindong & Xu Dongbing
Currently, IPTV faces key O&M challenges in three areas – network opacity, quality
of service (QoS), and subscriber complaint handling. A solution that can
comprehensively evaluate IPTV network performance and optimize service quality
would fill an urgent need for streamlined, efficacious O&M.
Challenges for IPTV O&M
New services, especially streaming media, are placing greater demands on the
network. IPTV would seem a perfect example, but a deeper analysis reveals that it is
actually not a great burden, thanks largely to subscriber apathy. A large number of
operators offer IPTV, but it excites no one anymore. It is one of those
once-ballyhooed flavors now growing stale in the display freezer after months of
sporadic tasting.
A great many operators released IPTV before their networks could deliver it as an
"ooh-ahh" experience. Content catalogs were often limited to third-rate titles that most
subscribers would not watch for free, while the image itself typically came across as
blocky and dull on a 42-inch screen. In other words, IPTV could not compete with
cable TV or physical media on any front, be it quality, selection, or price.
Today, thanks to industry advances (greater bandwidth, larger catalogs) and shifting
consumer tastes (growing intolerance of commercials, decreasing willingness to "tune
in next week"), IPTV would seem ready for its close-up; but it must be flawless this
time to overcome the horror stories spread by early adopters. Certain O&M issues
must be overcome for IPTV to be truly killer.
The primary hindrance is the fact that IPTV infrastructure has been thus far opaque.
Operators cannot see the resources that are idling, lacking, or redundant. Without
efficient resource leverage, at each & every stage, users now accustomed to Blu-ray
quality video will keep complaining that their picture looks bad enough to qualify as
UFO footage.
Another major hurdle has been a lack of KPIs that reflect IPTV quality of experience
(QoE). For most operators, IPTV service is a car with no dashboard. New indicators
are needed that both reflect actual user experiences and help operators analyze root
causes of service disruptions and hindrances.
The third major drag on IPTV service thus far has been its sensitivity to packet
drop/error, which is only increasing in the HD era, thanks to the compression
efficiencies, bit rates, and refresh rates involved. According to DSLAM Forum TR126,
seamless HD video transfer requires a ratio of packet loss/error below 10-7.
A step-by-step solution
Huawei offers an O&M facilitation solution (Huawei IPTV O&M) intended to meet
all operator IPTV needs for the foreseeable future. It is compliant with TM Forum
SLA management standards and incorporates technical raw indicators which are
inherently complex and difficult to understand, and integrates them along certain
dimensions such as time, measured target, and indicator type, into weighted mean
composite indicators which are simple and intuitive. Their analysis allows operators
to discover hidden patterns and problems.
Huawei IPTV O&M also enables operators to monitor service quality in real time,
assess it, rate performance for comparison, and locate faults in a quick, convenient
and transparent manner. Operators can also customize indicators, calculation methods,
and thresholds. This solution covers every phase of deployment, from network
bearing assessment to network design to pilot-release assessment to
commercial-release assessment.
Accurate network capacity assessment
Comprehensive assessment of network bearing capacity can include network
equipment assessment, capacity assessment, and service simulation. For the former,
Huawei IPTV O&M assesses the bearing capacity for layer-2 and layer-3 network
equipment, as well as home IPTV networking equipment.
As for capacity assessment, this solution examines IPTV traffic modeling and
available link bandwidth to determine numbers and locations of subscribers that the
network can bear. Service simulation encompasses all DHCP, PPPOE, VoD, multicast
service, and basic IPTV processes, yielding network MTU values and KPIs that are
output along with service simulation reports that include recommendations for various
scenarios.
Optimal network design
Huawei IPTV O&M aides the design of an optimal network that combines new
services and technologies with legacy infrastructure. This process can include services
such as basic network design, capacity and equipment planning/design, reliability
design, service process design, and network evolution solution design.
Tailored short-term assurance services
The reward for an IPTV pilot launch is usually a surge of complaints; aside from the
usual "squeaky wheel" logic that often drives such moaning, this can also stem from
improper installation and less-than responsive complaint handling by IPTV novices. If
not properly resolved, these problems will greatly hinder service growth. Huawei
helps by providing three to six months of short-term assurance services, customized
for each operator. Said services can be divided into four areas – release organization,
troubleshooting acceleration, efficacy testing, and staff training.
Commercial-scale assurance services
Service assurance is ongoing and may not get easier if there is rapid subscriber growth.
Huawei helps out by deploying a cascaded indicator system fed by various probes,
while a variety of tests, along with Huawei's expertise pool, can also be leveraged
continuously so that latent problems are nipped in the bud and QoE stays ahead of
usurpers.
A series of IPTV video quality probes are employed that can accommodate a variety
of scenarios, including mixed-vendor networking, QoE monitoring, timely onsite
troubleshooting, and all-channel video monitoring.
These probes may be software- (PC, STB, network hardware) or hardware-based
(external probes hung on network equipment). They function through video stream
diversion or mirroring-based optical split, and can monitor 10Mbps to 1Gbps video
streaming, so that E2E monitoring can be done for all channels.
As for fault location, Huawei IPTV O&M gives early warnings that help accelerate
the troubleshooting process through its E2E probe deployment and customized
indicator system. It also provides a robust and flexible detection toolkit, so that
maintenance personnel can preset detection rules/thresholds templates, based on their
own experiences. If a fault occurs, they simply need to start a combination of
detections and a report will be output as soon as possible.
Huawei IPTV routers feature built-in iVSE video boards that work with the U2520
monitoring/control system to realize "visualized and controllable" user experiences.
They also eliminate the pixelization that stems from packet loss/error.
With the RET retransmission mechanism, the user experience is guaranteed to remain
unaffected, even if the packet loss/error ratio reaches twenty percent, while the FCC
mechanism keeps the channel-switch interval below one second. More importantly,
all the preceding monitoring and control functions are automated and visualized.
In addition, Huawei has conducted in-depth research into the systematic assessment of
video quality, culminating in the vMOS algorithm, which takes into account a wide
variety of factors, including original quality, impact from the network, application
involved, and terminal involved, to better reflect subscriber QoE.
Real-world applications
This solution has been deployed by telecom operators worldwide. It effectively helps
them solve evaluation and optimization problems during network revamping while
providing strong support for the development of new IPTV services.
In the case of Etisalat (UAE), mixed-vendor networking was hindering transparency
for both network capacity and service experience, while QoE monitoring and fault
location across domains were non-existent.
Huawei provided a tailor-made IPTV evaluation and optimization solution that
enabled E2E fault location from the STB to the head end; it reduced the time spent on
fault location and daily checking by eighty percent, while IPTV QoE was also
significantly improved.
For China Telecom Shenzhen, Huawei offered a customized solution that included
systematic processes and methods for network-wide evaluation and optimization, and
an Internet AV service quality assurance solution for IPTV.
Through static analysis of network traffic and the operator's subscriber behavior
model, this solution predicts service requirements for network bandwidth growth and
thus sets the network indicator threshold model for long-term development.
It also provides comprehensive round-the-clock monitoring/control and assurance for
IPTV service through dynamic network evaluation, which enables objective
measurement of network bearing capacity and IPTV service operational status. China
Telecom Shenzhen can now optimize its network continuously from, and it has seen
significant improvements in its IPTV service experiences and network quality as well,
which should guarantee it market competitiveness for years to come.
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